Elevated unit substation access

[Fnewman]

A 1500 kVA unit substation (13.9 kV / 480 V) is to be installed on an elevated steel structure approximately 3.5 feet above the concrete pad below. A question has arisen with regard to the required front and rear access. Specifically, some are saying that while space is required, no elevated platforms (front or rear) are required as any periodic access can be provided using some sort of mobile platform. Now, don't shoot the messenger - my opinion is probably the same as the majority here - but can you point to any code requirement that would require elevated platforms?

 

[d0nut]

I could see running into an issue where your switches end up higher than allowed if you don't install the platforms.

 

[ron]

404.8(A) Location.
All switches and circuit breakers used as switches shall be located so that they may be operated from a readily accessible place. They shall be installed such that the center of the grip of the operating handle switch or circuit breaker, when in its highest position, is not more than 2.0 m (6 ft 7 in.) above the floor or working platform.

 

[Fnewman]

Perfect - Thanks

 

[paulengr]

That would make poke mounted gang operated switches never mind cutouts illegal. Not buying it.

Common to have a stair or ladder on one end and only a landing on the other. So you can “escape” just not very far.

 

[Hv&Lv]

Switching which side? Article 404 is for switches less than 1000V and padmount transformers aren’t really designed to have switches like that installed in them.

 

[zbang]

That would make poke mounted gang operated switches never mind cutouts illegal. Not buying it.

If you're thinking of PoCo stuff, that's not NEC territory.

(Is this sub under NEC or NESC?)

 

[paulengr]

If you're thinking of PoCo stuff, that's not NEC territory.

(Is this sub under NEC or NESC?)

You’ve never worked on industrial plants with medium voltage motors, or systems where outdoor equipment makes more sense. Lots of wood plants, large conveyor systems, iron and steel, chemical and petrochemical plants, water plants, mining operations all can fall under NEC either as a statutory requirement or voluntarily. The type of equipment does not make it “NESC”. In fact UL has recently been sticking their noses in it.

 

[zbang]

You’ve never worked on...

... then you haven't seen my CV, and that's not relevant anyway. Of course the type of equipment doesn't necessarily make it utility or customer but it's a fair question.